1. Field of the Invention
This invention relates to a sample supply device for supplying an inspection instrument, such as a flow cytometer, with a plurality of samples at high speed.
2. Description of the Related Art
Traditionally, sample supply to the inspection cuvette of a flow cytometer has been accomplished by pressurizing a tube containing a sample to be analyzed, causing the sample to flow into the sample supply line. Automation of this traditional supply method is difficult due to mechanical issues with automatic positioning and sealing of sample containers. Such a supply method is also prone to creating aerosols of biohazardous materials.
Another method of sample supply, which is sometimes implemented in flow cytometers, is aspiration of sample into the flow cytometer syringe pump and then expulsion of the sample into flow cytometer cuvette. One drawback of this method is that pulsations created in the sample flow can greatly amplify noise on the measured signal. Additionally, the amount of time required for washing between samples is great and slows the process for analyzing samples. The washing process cannot begin until sample has been fully dispensed into the flow cytometer cuvette, resulting in reduced throughput.
Another method of sample supply is described in U.S. Pat. No. 5,182,617, which is herein incorporated by reference in its entirety. The '617 patent discloses that higher throughput may be achieved by creating two identical branches that can perform simultaneous sample introduction and washing. When used, analyzed samples stick to the channels of the system, including the interface channels, causing major carryover issues in subsequent sample analysis. The prior art provides no provision for thorough washing of an interface channel between the sample supply device and the flow cytometer. Furthermore, the prior art fails to teach any provision for rapidly washing the system with a cleaning liquid.